1. Field of the Invention
The present invention relates to a projection device, and more particularly, to an adjusting apparatus for adjusting a light engine of the projection device.
2. Description of the Prior Art
In recent years, the dramatic development of electro-optical technologies has made data visualization a popular issue. The demand and importance for a projection device capable of displaying data have impressed the electronics industry. Therefore, projection device manufacturers make an effort to provide a projection device that produces high image quality.
Please refer to FIG. 1, which is a schematic diagram of a rear projection television according to the prior art. The television comprises a housing 11, a base 12 installed inside the housing 11, an adjusting apparatus 20 installed on an upward surface of the base 12, and a light engine 13 installed on an upward surface of the adjusting apparatus 20. The light engine 13 emits light beams that contain image information onto a first mirror 14 that is installed at a position in front of the light engine 13. The rear projection television further comprises a second mirror 16 installed at a position inside of a screen 15, the position being on a light path the light emitted by the light engine 13 reflects from the first mirror 14 onto the second mirror 16. The second mirror 16 reflects the light beams reflected from the first mirror 14 onto the screen 15. The light engine 13, the first mirror 14, the second mirror 16, and the screen 15 constitute a projection system of the television. To guarantee that the images projected by the projection system of the television onto the screen 15 do not contain any aberrations or distortions, the light engine 13, the first mirror 14, the second mirror 16, and the screen 15 of the projection system must be precisely adjusted and delicately fabricated to reduce any potential errors.
Please refer to FIG. 2, which is a schematic diagram of the adjusting apparatus 20 according to the prior art. The adjusting apparatus 20 adjusts the path the light beams emitted by the light engine 13 travel with a direction-adjusting apparatus. A raising screw 211 is installed on a central region of a downward surface of a horizontally disposed raiser 21 for controlling vertical movement of the raiser 21. A first displacement plate 22 is installed on a central region of an upward surface of the raiser 21. Two limited blocks 221 (only one is shown) are repectively installed on the raiser 21 beside two opposite sides of the first displacement plate 22 for preventing the first displacement plate 22 from moving to the left or right. A forward-and-backward adjustment screw 222 is installed on a front side of the first displacement plate 22 for controlling forward and backward movement of the first displacement plate 22. Similarly, a second displacement plate 23 is installed on a central region of an upward surface of the first displacement plate 22. Two limited blocks 231 are respectively installed on two opposite sides of the second displacement plate 23 for preventing the second displacement plate 23 from moving forward and backward. A left-and-right adjustment screw 232 is installed on a right side of the second displacement plate 23 for controlling left and right movement of the second displacement plate 23. Finally, a rotatable plate 24 is installed on a central region of an upward surface of the second displacement plate 23. A holder 241 is used for supporting the rotatable plate 24. A screw 242 is installed on a side of the rotatable plate 24 and controls the rotational motion of the rotatable plate 24. Therefore, the light engine 13, which is installed on the adjusting apparatus 20, can emit the light beams onto a region in any direction.
However, the bulk of the pile-structured adjusting apparatus 20 is contradictory to the design beliefs for modern information products: light, thin, short, and small. Additionally, the adjusting apparatus 20 can only rotate the light engine 13 horizontally (around a normal line of each of the plates of the adjusting apparatus 20), rather than vertically.